A powerful creature is bound to this amulet called Becanna Edune. As an action, you can cast Find Familiar to summon it in the form of a Twig Blight,  appearing in an unoccupied space within range. When you do so,  you may use this amulet as an additional component, which is not consumed by the spell (the standard components are still required and consumed). 

As a bonus action, if within 5 feet of your Twig Blight familiar, you may merge it with the amulet. The Twig Blight is sucked into the amulet, disappearing. When merged, the amulet grants you +1 to your spell attack modifier and Spell Save DC. If the familiar dies, the bonus will not apply.

As a bonus action, if your Twig Blight familiar is merged with this amulet, you may cause it to un-merge and appear in an unoccupied space within 10ft. 

Your Twig Blight familiar, in all other ways, acts as a standard familiar per the spell.

Notes: Bonus: Spell Attacks, Bonus: Spell Save DC, druid, Summoning, Buff, Combat, Jewelry